<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>jQuery对象转成DOM对象案例</title>
    <script type="text/javascript" src="../js/jquery-1.4.2.js">

    </script>
</head>
<body>
<input type="text" value="zhang" id="username" name="username" />
</body>
<script type="text/javascript">
//JQUERY对象转化为DOM对象
var $inputObj = $("#username");
//    alert($inputObj.val());

    //转化成DOM对象：方法一
    var demObj = $inputObj[0];
    alert(demObj.value);

    //way 2
    var domObj = $inputObj.get(0);
    alert(demObj.value);

</script>
</html>